CDKN2A and lung cancer: Furthermore, genetic testing of the lung cancer demonstrated genomic alterations in ARID2 and KEAP1. Whereas the clinical significance of KEAP1 is not known, ARID2-inactivating mutations have been found in 5% of non-small cell lung cancers and are considered one of the most frequent mutated genes after TP53, KRAS, EGFR, CDKN2A, and STK11 [22].